We provide the first publicly available statistics on the extent to which recent successive birth cohorts enter Social Security Disability Insurance (SSDI), and on cross-cohort trends in the average number of years of SSDI benefit receipt among cohort members. We find that the percentage of each birth cohort entering SSDI by ages 45, 50, and 55 is increasing. Mean years of benefit receipt among all individuals in the birth cohort has grown even more rapidly, due to the combined effects of entry at younger ages and lower mortality after entry. Our findings account for immigration, an important factor that is often ignored in discussions about growth in the SSDI rolls. Annual SSDI awards have declined sharply since 2010, after rising rapidly on the heels of the Great Recession. During the same period, the birth cohort data show a decline in SSDI entry by age 40, and a diminished rate of growth by age 55. Still, in 2014—the last year of our data—the rates of entry by ages 45 and 50 are well above what they were 10 years earlier. Viewing the data from the perspective of cohorts shows that there remains an urgent need to test and adopt policies to reduce avoidable labor force exit and SSDI entry by workers who experience work-threatening medical problems.